This is a request for funding for a Symposium on the topic of "Psychoactive Drugs, Immunity and Immunodeficiency, "co-sponsored" by the National Institute on Drug Abuse, the National Institute on Alcoholism and Alcohol Abuse, and the University of South Florida College of Medicine. The relationship of drugs of abuse as possible co-factors in AIDS is of a major concern to many biomedical scientists and clinicians. If one takes into consideration the large number of non-i.v. drug abuser subjects who are at risk, it is obvious that such individuals are co-abusers of drugs of abuse and alcohol. There has been a recent reevaluation of the possibility that such drugs are immunosuppressive. The major goal of the proposed Symposium is to bring together internationally renown scientists to discuss not only what has been done in terms of examining the nature and mechanisms of immunomodulation by drugs of abuse such as marijuana, cocaine, opiates and alcohol , but also important parameters which must still be examined in both man and experimental animals to define the nature and mechanisms whereby such agents influence immunity. This symposium will lead to a greater awareness of the necessity to study in much greater detail the mechanisms whereby drugs of abuse influence the immune response system in a co-factor role to the AIDs epidemic. We believe such a meeting will be a highly cost effective and efficient method to bring together some of the world renown investigators in the area of psychoactive drugs and immunodeficiency.